DE3921174C2 - - Google Patents

Description

The invention relates to a line element for the first one of several line elements, namely raw pipes, pipe parts and pipe connections set line system, the line element in essential from uncrosslinked, after shaping and after assembly of the piping system by access or feed of moisture-crosslinkable plastic.

Pipe systems come in almost al today areas of technology. So at for example piping systems for the transport of large menus gene of a medium, such as water, gas or Oil used over long distances. Even lei systems for the transport of difficult to handle Media, such as acids or bases, advantageous use. When installing the house, pipes systems both as open systems, e.g. B. for industrial water lines, as well as in closed circuits, e.g. B. for heating lines. Furthermore, Lei systems as industrial pipelines for the Trans port of gases, liquids and also pourable solid fabrics used. As pneumatic tube systems, line sys systems also used for "message transmission" the. There are also a variety of applications in control technology, e.g. B. for compressed air and hydraulic lines exercises.  

Line systems are known in which the line elements made of thermoplastic materials, such as polyethylene len, polypropylene or polyvinyl chloride (PVC) exist. The tubes are processed in a conventional extrusion process drive and through the pipe parts and pipe connectors Injection molding or forming. According to the type of The use of the piping system also targets the out choose the "right" type of connection. So it’s enough off, with unpressurized lines, such as wise house drain pipes, with appropriate connec end-provided line elements in the form of a Simply push the push-in joint together.

Pressurized line systems demand permanently secure connections, including the line elements depending on used material by welding, gluing, screwing ben or terminals are interconnected.

The use of thermoplastics for manufacture position of line system parts has the disadvantage that the components of a piping system thus produced to crawl under pressure and temperature tend. The creep behavior of partially crystalline ther Moplastic is by the wrinkle of time standing curves shaped. Better creep behavior with linear creep curves and less tendency to creep show cross-linked plastics because of the cross-linking a coherent network of molecules is formed, as this from "Plastic Technology" (Febr. 1981), pp. 83-86. Line elements from ver however, netting plastics have the disadvantage that they can no longer be connected by welding can, so that to assemble a piping system from the like pipe elements with pipe connectors Metal or mechanically more resilient thermoplastic engineering plastics, need to be connected. Such connectors are as  Clamp or screw connections. Because with that the previously described piping system mentioned above spoken undesirable creep behavior occurs, it can in the area of connections, especially under the influence of Pressure and temperature, to leaks in the pipe system stem come. If connectors made of metal are used, so must have rubber sealing rings or the sealing elements same sealant can be used, but at some uses of the pipe system not at all or can only be used for a limited time. Become pipes or pipe parts made of cross-linked plastic with ge injection molded thermoplastic plastic pipe connectors combined from "engineering plastics", depending on Type of turned on for the pipes and pipe parts plastic is highly susceptible to hydrolysis, especially in hot water applications. There are hydrolysis-resistant "engineering plastics" is known, but because of their extremely high prices they are not for Pipe connectors are used.

Furthermore, line systems are made of composite materials knows. The line elements are a multi-layer components made of metals (aluminum, copper, steel, etc.) and thermoplastic or cross-linked plastics leads. This is disadvantageous with such line elements different expansion behavior of the materials Me tall and plastic with temperature changes. Tensions through the different expansion behavior, however also corrosion of the metal layers due to moisture speed, also due to the low water level vapor permeability of the plastics lead to a Delamination of the individual layers and thus to one Destruction of the pipe system. Furthermore, such lei tion elements made of composite materials due to the manufacturing a high price.

The present invention is therefore based on the object reasons, the line element specified at the beginning for Er design of a piping system and so terzubilden that the aforementioned disadvantages avoided be and that a good creep behavior of the whole Pipe system with easy manufacture of the connector reached between the individual line elements becomes. A long service life is also desirable universal application range at a reasonable price.

The object is achieved according to the invention with one Pipe element of the type mentioned with the kenn characterizing features of claim 1.

With the invention, a line element is created which allows the properties in terms of Connectivity to the respective needs, which depend on the customer depend on application and area of application, optimally adapt sen, d. H. in particular, the line element a network availability only in the areas or parts, where necessary. This allows the amount of for to achieve the cross-linkability of the plastic relatively expensive aggregates are reduced, the savings achieved here making it more expensive exceeded by the somewhat increased manufacturing effort fen. In addition, line elements according to the invention easier and more effective against an unwanted early start of networking in their networkable part len or areas are protected, what the quality of the piping systems created from this is significantly better sert. Suitable as base material for the pipe element especially polyethylene.

The non-crosslinkable part of the lei preferably has tion element the shape of a layer, since this shape for many applications is the most suitable and also in the Production of the line element is easy to generate.  

An embodiment of the line element provides that also its non-crosslinkable part made of plastic stands, which also leads to a simple production of the Line element contributes. This is plastic preferably impermeable to water vapor, which makes this as a moisture barrier to avoid unwanted th premature networking of the networkable parts of the Line element can be used. To a damp Avoiding access from the outside is advisable non-crosslinkable part of the plastic as an outer layer educated.

Alternatively, the non-networkable part of the art fabric also formed as an outer jacket and with the Lei tion element be removably connected. This outside man tel also provides an integrated moisture barrier re, but is advantageously quick and easy and without any special tools from the rest of the line element removable.

In another embodiment, the non-networkable re part by coextrusion firmly with the rest of the pipe element connected. This results in a better, stop barer moisture barrier for the networkable part of the Line element. If necessary, this can also be damp activity lock, e.g. B. in the area of connection points, can be removed by machining.

Further embodiments of the invention provide that the line element does not crosslink a metal layer bare layer and that this either in the tub extension of the line element embedded or as an outside layer or jacket applied to the line element is. This also makes an effective moisture barrier re created, the mode of action of which the previous described locks corresponds. The metal layer be is preferably made of aluminum, since this is light  and is corrosion resistant.

In many applications, a subsequent Ver is sufficient the interconnected line elements in their connection area, which is why the invention sees that the non-networkable part of the line element tes the Be between its junctions richly embraces.

To also trigger a networking from the inside Entry of moisture into the interior of the line element Prevent mentes before creating the piping system which, it is finally provided that the ends removable, moisture-proof closures exhibit.

With line elements according to the invention, rela tiv simple and inexpensive safe and long lasting Create line systems that are advantageous z. B. for Heating systems and domestic water systems in the house installation, for gas and liquid lines in the chemical and food industries as well as for many let other purposes be used.

Claims (12)

1. Line element to create a line system composed of several line elements, namely pipes, Rohrleitungstei len and pipe connectors, the line element essentially from uncrosslinked, after the formation and after the days of the line system by access or supply of moisture-crosslinkable plastic be stands, characterized in that the line element has a non-crosslinkable part. 2. Pipe element according to claim 1, characterized net that the non-crosslinkable part in the form of a Layer. 3. Pipe element according to claim 1 or 2, characterized ge indicates that the non-crosslinkable part Plastic is made. 4. Pipe element according to claim 3, characterized net that the non-crosslinkable part Plastic is a water vapor impermeable plastic is. 5. Pipe element according to one of claims 1 to 4, there characterized in that the non-crosslinkable part of the plastic is formed as an outer layer.   6. Pipe element according to one of claims 1 to 4, characterized in that the non-crosslinkable Part of the plastic formed as an outer jacket and is removably connected to the line element. 7. Pipe element according to one of claims 1 to 5, there characterized in that the non-crosslinkable part by coextrusion firmly with the pipe element connected is. 8. Pipe element according to claim 2, characterized net that there is a metal layer as non-crosslinkable Has layer and this in the wall of the Lei tion element is embedded. 9. Pipe element according to claim 2, characterized net that there is a metal layer as non-crosslinkable Has layer and this as an outer layer on the Line element is applied. 10. Pipe element according to claims 8 and 9, characterized characterized in that the metal layer of aluminum consists. 11. Pipe element according to claim 1, characterized net that the non-networkable part of the Leiterele mentes the between its junctions covers the area. 12. Pipe element according to one of claims 1 to 10, characterized in that its ends are removable, have moisture-proof closures.